Prince Harry reunites with his biggest fan for the third time in Sydney

Prince Harry has reunited with his biggest fan for the third time during the first day of the Australian Royal Tour.

War widow Daphne Dunne, 98, was front and centre of the crowd eagerly waiting for the Duke and Duchess of Sussex outside the Opera House — and her patience paid off, with Harry greeting her like an old friend.

The pair embraced warmly and chatted about the weather.

Daphne Dunne is reunited with Prince Harry - this time, with his wife. (9News)

"We understand each other," Dunne told 9News of their encounter, saying she and the prince share a special relationship.

The 98-year-old famously stole a kiss from Harry during his visit to Australia in 2017; two years later, the pair met again in the pouring rain when Harry was in Sydney for the Invictus Games launch.

Daphne Dunne and Prince Harry were reunited a second time in 2017. (AAP)

This time around, Dunne also met her beloved prince's new wife, Meghan Markle, who appeared equally charmed by the war widow as she crouched down to speak with her.

The verdict? "She's lovely."

(Getty)

Meghan and Harry chat with Daphne Dunne. (Getty)

Unfortunately, it seems pregnancy side-effects - and jetlag from the long-haul flight from the UK - may have taken their toll on the Duchess today.

An official outside the Opera House told 9Honey the 37-year-old expectant mum, whose pregnancy was confirmed by Kensington Palace on Monday evening, wasn't feeling well suggesting the meet-and-greet could have been longer had she felt up to it.

WATCH: Meghan Markle greets crowds at the Sydney Opera House

Catch up on the other highlights of Day 1 of the Australian Royal Tour below:

The Duke and Duchess of Sussex took their time as they greeted countless fans gathered outside the Opera House, many of them students.

The pair shook hands and chatted with their well-wishers, several of whom presented them with gifts and cards.

Meghan Markle chats with fans outside the Opera House. (9News)

The royals attracted a large crowd. (9News)

Before their meet-and-greet, Meghan and Harry enjoyed a performance by the Bangarra Dance Company at the Sydney Opera House, having travelled to the iconic landmark via ferry from Taronga Zoo.

Security sweeps were carried out around the venue ahead of the couple's arrival, with a sniper positioned overhead.

Prince Harry and Meghan Markle arrive at Circular Quay. (Getty)

Meghan and Harry enjoy a performance by the Bangarra Dance Company. (9News)

The occasion marked their first time meeting with members of the Australian public as a couple - the first of many to come during their Royal Tour.

9Honey's reporter on the ground, Natalie Oliveri, said fans waiting in the crowd waved Aussie flags and were eager to know every detail of the couple's day in the Harbour city so far.

WATCH: 9Honey meets some of the royal fans gathered outside the Opera House for a chance to meet Harry and Meghan. (Post continues.)

The Opera House stop followed Harry and Meghan's visit to Taronga Zoo to open the new Taronga Institute of Science and Learning.

While at the zoo, the couple ticked off a very important Aussie bucket list item: meeting a koala and her newborn joeys.

In an extra special twist, the babies are named Harry and Meghan.

A very special koala encounter. (AAP)

The gesture was a wedding gift to the royal couple from the NSW Government, announced when they tied the knot in May.

Earlier in the morning, they joined Governor General Sir Peter Cosgrove and Lady Cosgrove at Admiralty House, meeting with representatives of the 18 countries competing in the Invictus Games.

The couple, who will spend a total of 16 days in Australia, New Zealand, Fiji and Tonga, were presented with a belated wedding gift on behalf of Australia: Akubra hats.